JPH01316742A - Packaging material for photosensitive material - Google Patents

Abstract

PURPOSE:To improve heat sealability and physical strength by laminating specific uniaxially molecular oriented films which are multilayered and co-extruded and at least one more different uniaxially molecular oriented films in such a manner that the molecular orientation axes thereof intersect with each other. CONSTITUTION:The uniaxially molecular oriented films which are multilayered and co-extruded and have the high-density polyethylene (HDPE) resin film layer 1a contg. >=50wt.% HDPS having >=0.941g/cm<2> density, 0.1-1.0/10min melt index and >=120 deg.C softening point and the straight chain low-density polyethylene (LDPE) resin film layer 2a having <=0.940g/cm<2> density and 0.5-15.0g/10min melt index and at least one more difference uniaxially molecular oriented films are laminated in >=2 sheets in such a manner that the molecular orientation axes thereof intersect with each other. The physical strength and heat sealability are improved in this way and the packaging material is inexpensively produced.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a packaging material suitable for packaging photosensitive materials, particularly photographic materials.

(Prior Art) Various types of packaging materials for photosensitive materials are in widespread use, and various performances are required depending on the intended use.

Packaging materials that completely block light are used as packaging materials for photosensitive materials that lose their quality value when exposed to light. In this case, the required properties include packaging material slit suitability, gas barrier properties, light blocking properties, moisture resistance, rigidity, and physical strength (breaking strength, tear strength).

impact drilling strength, gelbo test strength, friction strength, etc.) heat sealability (heat seal strength, cut sealing properties, hot tack properties, contaminant sealing properties, etc.), antistatic properties, flatness, sliding properties, etc.

Conventionally, packaging materials for photosensitive materials have been high-pressure branched low-density polyethylene (hereinafter LDPE) mixed with carbon black.
As shown in FIG. 13, high-density polyethylene (hereinafter referred to as HDPE) resin film 9
There was a composite laminate film made by laminating multiple films.

As the composite laminate film, for example, as shown in FIG. 14, an LDPE resin film 7a containing a light shielding substance is used.
・Put the metal foil 11 and the flexible sheet 5 between 7a,
There was a film laminated with adhesive N3...3.

Further, as shown in FIG. 15, on both sides of the metal foil 11, there was a film in which uniaxially stretched films 8a, 8a having a predetermined stretching ratio were laminated so that the stretching axes were at a predetermined angle.

(Utility Model Publication No. 61-20590).

Furthermore, as shown in FIG. 16, on both sides of the metal foil 11,
Linear low-density polyethylene (hereinafter referred to as L-LDPE)
There is a laminated film in which carbon black is added to the resin and LDPE resin films 10a and 10a are laminated (Japanese Unexamined Patent Publication No. 189438/1983, etc.).

[Problem to be solved by the invention] However, LDPE mixed with carbon black
Packaging materials such as resin films and HDPE resin films shown in Figure 13 have poor heat sealability and physical strength (particularly tear strength and impact puncture strength), and may become punctured or torn during packaging or transportation. The heat-sealed part may peel off, making it difficult to ensure light-shielding, moisture-proofing, and gas barrier properties, making it difficult to put it to practical use, especially as a sealed light-shielding bag for roll-shaped photosensitive materials or sheet-shaped photosensitive materials weighing more than 1 kg. It was difficult.

In addition, LDPE containing carbon black as shown in FIG.
Films made by laminating M-fat film, aluminum foil, and flexible sheets have low physical strength such as tear strength despite their thickness, and are not suitable for heat sealing, resulting in bag breakage and heat damage during packaging and transportation. The seal portion peeled off, making it difficult to ensure light-shielding properties, moisture-proofing properties, and gas barrier properties, and moreover, it was expensive.

In addition, the cross-laminated film shown in FIG.
Since it is composed only of DPE resin film, it has low impact puncture strength, poor heat sealability, and is expensive because it requires a lamination process in which flexible sheets are laminated.

Furthermore, L-LD containing carbon black as shown in FIG.
The laminated film made of PE resin film has good heat sealability, tear strength and impact puncture strength.
Although it is inexpensive and excellent as a packaging material for photosensitive materials, L-L
The laminated film of DPE resin film and aluminum foil has a small Young's modulus, so it lacks tensile strength and bursting strength.
The laminated film is stretched and becomes thinner, and although no holes or tears occur, the problem arises that it cannot ensure light-shielding and moisture-proofing properties.

For this reason, although expensive, nylon resin films or polyester resin films laminated with vacuum-deposited aluminum, which have a high Young's modulus and heat resistance, have been put into practical use. However, this method requires a lamination process for lamination, and also has the disadvantage that losses occur during the aluminum vacuum deposition process, biaxially stretched film manufacturing process, etc., resulting in an expensive packaging material.

The present invention solves the above problems, has excellent heat sealability, excellent physical strength (tensile strength, tear strength, impact puncture strength, bursting strength, etc.), and is effective in ensuring the quality of photosensitive materials such as light shielding properties, moisture proofing properties, and gas barrier properties. The object of the present invention is to provide an inexpensive packaging material for photosensitive materials that can ensure all necessary properties without using other flexible sheets.

[Means to solve the problem]

The present invention has been made to achieve the above object, and includes a multilayer coextruded uniaxially molecularly oriented film having an HDPE resin film layer and an L-LDPE resin film layer, and at least one different uniaxially oriented film. This problem was solved by laminating molecularly oriented films so that their molecular orientation axes intersect.

The multilayer coextruded uniaxially molecularly oriented film of the present invention and at least another different uniaxially molecularly oriented film that are laminated so that the molecular orientation axes intersect are resin compositions, molecular orientation axes,
It is sufficient that the degree of molecular orientation (including stretching ratio), number of film layers, and film layer structure are different from those of the multilayer coextruded uniaxially molecularly oriented film of the present invention. In particular, when laminating on the surface (anti-heat sealing side), use a uniaxially oriented film with a high melting point, and when using it as a heat seal layer, use a uniaxially oriented film containing ethylene copolymer resin with excellent heat sealability. It is preferable to use

That is, the packaging material for photosensitive materials of the present invention has a density of 0.9.
41 g/cJ or more and melt index of 0.1 to 1.
0 g/10 minutes, a high density polyethylene resin film layer containing 50% by weight or more of high density polyethylene resin with a softening point of 120°C or higher, and a melt index of 0.5 to 15.0 g with a density of 9.40 g/cj or lower A multilayer coextruded uniaxially molecularly oriented film having a /10 minute linear low density polyethylene resin film layer and at least one other different uniaxially molecularly oriented film, two or more sheets such that the molecular orientation axes intersect. The structure is characterized by comprising at least one layer that is laminated and has a light-shielding property.

The IDPE resin film layer has a density of 0.941 g/d
With the above, the melt index (hereinafter referred to as Ml) is 0.1
Contains 50% or more of HDPE resin at ~1.0g/10min. If this HDPE resin is less than 50% by weight, the molecular orientation is insufficient and tear strength as a laminated film cannot be ensured sufficiently, and the density is 0.941 g/c.
If it is less than n, the molecular orientation will be insufficient and the film surface strength, Young's modulus, cross-laminate effect, etc. will be small, and the purpose of improving physical strength will not be met.

Furthermore, if Ml is less than 0.1 g/ci&, the motor load increases, the amount of resin discharged decreases, and the film formability decreases. In particular, practical problems arise when trying to add a light-blocking substance. When the MI exceeds 1.0 g/10 minutes, molecular orientation is insufficient and tear strength as a laminated film cannot be ensured sufficiently. In the present invention, a uniaxially molecularly oriented film refers to a film in which the difference between the tear strength in the direction of the molecular orientation axis and the tear strength in the direction perpendicular to the molecular orientation axis is 1.5 times or more.

The HDPE resin effective in the present invention is a polyethylene resin obtained by a medium-low pressure method, and has a density of 0.941 to 0.975.
The IDPE resin film layer used in the present invention is preferably one having a linear structure with few branches obtained by a low-pressure method, having heat resistance, and having a low crystallinity. It has a high Young's modulus, which easily causes crystallization and molecular orientation immediately after film forming, and has a large Young's modulus within the above characteristic value range.

The other resin used for this IDPE resin film layer is preferably a polyolefin resin, which improves physical strength,
Ethylene copolymer resin is particularly preferred from the viewpoint of improving heat sealability.

Furthermore, the IDPE resin film layer has a softening point of 120
″C or higher is preferable.

The density of the L-LDPE resin film layer is 0.940g.
/c- or less, Ml is 0.5 to 15.0 g/10 min L
- Contains 301!1% or more of LDPE resin. This L
-If the LDPE resin content is less than 30% by weight, physical strength and heat sealability will decrease. Also, the density is 0.940
If it exceeds g/ad, the impact puncturing strength will decrease, molecules will be more likely to be oriented in the longitudinal direction, and the tear strength in the longitudinal direction will be significantly reduced. Furthermore, heat sealability is also deteriorated. Furthermore, M
If l is less than 0.5 g/10 minutes, the fluidity of the resin will be insufficient, so the current load will increase, the film forming speed will decrease, and melt fracture will occur, making the film surface rough and impractical. If it exceeds 15.0 g/10 minutes, not only will the physical strength decrease, but the bubbles will become unstable, causing thick and thin unevenness and streaks.

L-LDPE resin is referred to as the third polyethylene resin, and is a low-cost, high-strength resin that meets the demands of the times for energy and resource conservation, combining the advantages of medium-low density and high-density polyethylene resins. This resin, which is preferred in the present invention, is produced by a low-pressure method or a high-pressure modification method in which ethylene and a carbon number of 3 to 1 are combined.
It is a low-medium-density polyethylene resin that is a copolymer of 3, preferably 4 to 10 α-olefins, and has a linear structure with short branches.

α-O, butene-11 octene-1 as reflexin,
hexene-1,4-methylpentene-1, heptene-1
, etc. are used. The density is generally considered to be about that of low-medium density polyethylene resin, but the density used in the present invention is 0.87.
~0.940 g 10 il of Shi-LDPE resin.

Specific examples of L-LDPE resins by trade name include G Resin, TUFLIN, Nucflex (U00), Dowlex (Dow Chemical), Sflare (DuPont Canada), Marlex (Philips), and Fselen ( Resident Chemical), NUC Polyethylene-LL, TUFT
Examples include HENE (Nippon Unicar), Neozex and Ultzex (Mitsui Petrochemicals), Megasu Nilex (Nippon Petrochemicals), Idemitsu Polyethylene-L, MORETEC (Idemitsu Petrochemicals), and Stamilex (DSM).

As the other resin used for this L-LDPE resin film layer, polyolefin resins are preferred, and ethylene copolymer resins are particularly preferred. In addition, it is preferable to add carbon black, a lubricant, an antiblocking agent, and an antioxidant to the L-LDPE resin film layer.
For example, 0.01 to 5.0% by weight of silicon dioxide, 0.05 to 20.0% by weight of carbon black, plate-shaped substances with a layered crystal structure (talc, aluminum powder, aluminum paste, pyroferrite, kaolin, It is preferable to add 0.05 to 5.0% by weight of sericite, etc.) from the viewpoint of preventing blocking and improving light-shielding properties.

In addition, the L-LDPE resin film layer has a softening point of 10
The temperature is preferably 5° C. or lower in terms of improving physical strength and heat sealability.

At least one is formed of a multilayer coextruded uniaxially molecularly oriented film having an HDPE resin film layer and an L-LDPE resin film layer as described above.

The molding method and molding machine for this multilayer coextruded uniaxially oriented film include, for example, JP-A No. 47-34656, JP-A No. 48-100464, and JP-B No. 40-5319.
No. 47-38621, No. 47-3992
Publication No. 7, Publication No. 53-18072, USP 3,3
There are equipment and methods of the type disclosed in Publication No. 22.613 and others. Conventional known methods and molding machines can be used to form the horizontally or vertically oriented molecularly oriented film.

In the present invention, a -axis molecularly oriented film refers to a film in which the difference between the tear strength in the direction of the molecular orientation axis and the tear strength in the direction perpendicular to the 11-minute molecular orientation axis is 1.5 times or more. In the present invention, the direction in which the tear strength is small at this time is defined as the uniaxial molecular orientation direction.

The molecular orientation method is the most commonly used stretching method, or the method of discharging from a narrow slot opening using a highly crystallized resin that is easy to orient molecules. For example, a blown film having a tear strength in the vertical direction of 50 g and a tear strength in the horizontal direction of 300 g is defined as a vertically oriented molecularly oriented film.

In addition, this multilayer coextruded uniaxially oriented film is HDP
As long as it has an E resin film layer and an L-LDPE resin film layer, a film layer made of various thermoplastic resins or the like may be laminated by coextrusion between or on the outside thereof. The molecular orientation axis of this multilayer coextruded uniaxially molecularly oriented film is vertical;
It may be horizontal or diagonal. The above multilayer coextruded uniaxially molecularly oriented film essential to the present invention and at least one other uniaxially molecularly oriented film laminated so that the molecular orientation axes intersect are the above multilayer coextruded uniaxially oriented film essential to the present invention. The layer structure, resin composition, etc. may be different from those of the molecularly oriented film, and the film may be a single-layer, axially molecularly oriented film. Further, it may be a knee-axis molecularly oriented film of a metal thin film agent or a film that does not have light-shielding properties. It may be a molecularly oriented i-film or a knee-axis molecularly oriented film, or it may be a film that does not have light-shielding properties. The molecular orientation axis may be vertical, horizontal, or oblique.

Such a multilayer coextruded uniaxially molecularly oriented film and at least one different uniaxially molecularly oriented film are directly laminated with or without an adhesive layer so that their molecular orientation axes intersect. The adhesive for laminating this multilayer coextruded uniaxially oriented film and at least one other uniaxially oriented film may be polyolefin thermoplastic resins such as various polyethylene resins, various polypropylene resins, polybutene resins, polyisobutylene resins, etc. Hot melt adhesive, ethylene-propylene copolymer resin, ethylene-vinyl acetate copolymer resin, ethylene-
There are thermoplastic resin hot melt adhesives such as ethylene copolymer resins such as ethyl acrylate copolymer resins, ethylene-acrylic acid copolymer resins, and ionomer resins, and other hot melt type rubber adhesives. Examples of adhesives include adhesives for wet lamination, such as emulsion and latex-based adhesives. Typical examples of emuldigon adhesives include polyvinyl acetate resin, vinyl acetate-ethylene copolymer resin, vinyl acetate resin and acrylic ester copolymer resin, vinyl acetate resin and maleic ester copolymer resin, and acrylic acid ester copolymer resin. There are emulsions such as copolymer resins and ethylene-acrylic acid copolymer resins.

Typical examples of latex adhesives include natural rubber, styrene butadiene rubber (SBR), acrylonitrile butadiene rubber (NBR), and chloroprene rubber (CR).
There are rubber latex such as Furthermore, examples of adhesives for dry lamination include isocyanate adhesives and urethane adhesives. In addition, known adhesives such as hot melt laminating adhesives, pressure sensitive adhesives, heat sensitive adhesives, etc. blended with paraffin wax, microcrystalline wax, ethylene-vinyl acetate copolymer resin, ethylene-ethyl acrylate copolymer resin, etc. Can be used. More specifically, polyolefin resin adhesives for extrusion lamination include various polyethylene resins,
In addition to polyolefin resins such as polypropylene resin and polybutylene resin, and ethylene copolymer (EVA, EEA, etc.) resins, resins such as L-LDPE resin that are made by copolymerizing some other monomers (α-olefin) to the ethylene linear chain Ionomer resins (ionic copolymer resins) such as DuPont's Surlyn, Mitsui Polychemical's Himilan, Mitsui Petrochemical's Atomer, and Mitsubishi Yuka's MOD.
There are ICs (adhesive polymers), etc.

The thickness of the adhesive layer made of such an adhesive is 50 mm in terms of physical strength improvement (particularly tear strength). It is preferably at most 20 microns, most preferably at most 13 microns.

A flexible sheet layer can be laminated between or on the outside of this multilayer coextruded uniaxially molecularly oriented film.

As this flexible sheet layer, known films such as thermoplastic resin films such as various polyethylene resins, ethylene copolymer resins, polypropylene resins, polyvinyl chloride resins, polyvinylidene chloride resins, polyamide resins, polycarbonate resins, and polyester resins, There are films including non-oriented films, multi-axis molecularly oriented films, modified resins, mixed resins, crosslinked resins, etc. of these films. In addition, metal thin film processing films (typically aluminum vacuum-deposited films), cellulose acetate films, cellophane, polyvinyl alcohol, various papers (especially preferred are neutral paper, dust-free paper, and synthetic paper), and various metal foils. (A typical example is aluminum foil), nonwoven fabric, etc.

A particularly preferable flexible sheet layer has a basis weight of 20 to 40
Various types of 0g/rrf (unbleached kraft paper, semi-bleached raft paper, bleached raft paper, bleached rulphide paper, twisted base paper,
Talpack paper, Duostress paper, white paperboard, photographic base paper, pure white roll paper, coated paper, imitation paper, neutral paper, glassine paper, etc.), metal foil with a thickness of 5 to 50 mm (aluminum foil, tin foil, zinc tube) , lead foil.

iron foil, etc.) biaxially stretched thermoplastic resin film,
Examples include cellophane, aluminum vacuum-deposited paper, metal thin film processed film (typically aluminum vacuum-deposited thermoplastic resin film), and the like.

In addition, the packaging material for photosensitive materials of the present invention has a small number of layers (one layer in total) having a light-shielding property that blocks visible light and ultraviolet rays.This light-shielding layer includes an HDPE resin film layer, an L- LDPE resin-based film layer, one or more uniaxially oriented films intersectingly laminated with the multilayer coextruded uniaxially oriented film of the present invention, an adhesive layer, and, if laminated, an intermediate layer, It may be a metal foil, a metal thin film processed film, or other various flexible sheet layers.

In order to have a light-shielding property, it may be formed of metal foil, processed into a metal thin film, or added with a light-shielding substance. This light-shielding substance can be kneaded or dispersed in each layer and does not transmit visible light, ultraviolet rays, etc. Light-shielding substances that can be used in the present invention include various carbon blacks, graphite, graphite, iron oxide, zinc white, titanium oxide, clay, aluminum powder, aluminum paste, calcium carbonate, mica, barium sulfate, talc, and cadmium pigments. , Bengara, cobalt blue, copper phthalocyanine pigments, monoazo or polyazo pigments, aniline black and other organic pigments, inorganic pigments, and coloring dyes.

Among these light-shielding substances, in terms of quality, cost, light-shielding ability, etc., colored pigments that easily absorb or reflect light, especially various carbon blacks of black pigments, and light-reflecting light-shielding substances such as aluminum powder and aluminum. It is preferable to use a paste with lower volatile matters removed than a paste.

Methods for blending these light-shielding substances into each layer include the masterbatch coloring method, die color granulation method, compound coloring method, dry color method, liquid color method, and the like, which have been commonly used in the past. The above-mentioned light-shielding substances may be used in various forms, such as powder colorants, granular colorants, paste colorants, moisturizing colorants, master patch pellets, dyes and pigments, and colored pellets, depending on the resin used, the machine used, cost, etc.

Carbon black is classified into gas black, oil furnace black, channel black, anthracene black, acetylene black, oil smoke, powder smoke, aniline black, vegetable black, etc. depending on the raw material.

Among these carbon blacks, carbon blacks with a pH of 5 to 9, especially those with a pH of 116 to
8. Those having an average particle size of 10 to 200 mμ are preferable, and furnace black and acetylene carbon black having a pH of 6 to 9 and an average particle size of 15 to 80 mμ are particularly preferable. By using a material with such pH and particle size, there is less fog in the photographic light-sensitive material, less increase or decrease in photosensitivity, greater light shielding ability, and the ability to prevent lump-like non-uniform substances, fish eyes, etc. Packaging materials can be produced that have a number of advantages, such as being less likely to have pinholes. Furthermore, when used as a packaging material for photographic light-sensitive materials, it is preferable to use carbon black with a free sulfur content of 1000 ppm or less in order to stabilize anti-capri photosensitivity.

In the packaging material for photosensitive materials of the present invention, furnace carbon black is preferred from the viewpoint of improving light-shielding properties, cost, and physical properties, and acetylene carbon black and ketchiene carbon black, which are expensive but have an antistatic effect, are also preferred. Channel black is undesirable because it is expensive and has a negative effect on photographic materials.

Carbon black content is 0.05-20.0% by weight
is preferred. If the weight is less than 0.05 weight, it is necessary to laminate another light-shielding layer to ensure light-shielding properties.20.0
If it exceeds % by weight, the physical strength and heat-sealability of the film will decrease, and lump-like non-uniform substances will increase, resulting in an increase in cost.

In the packaging material for photosensitive materials of the present invention, antioxidants, lubricants, and other additives are added to improve the thermal stability, other performance, and ease of handling of the multilayer coextruded uniaxially molecularly oriented film. preferable.

As antioxidants, phenolic ones include n-
Octadecyl-3(3',5'-di-L-butyl-4'hydroxyphenyl)propinate, 2,6-di-t-butyl-4-methylphenol, 2,6-di-t-butyl-p-
Cresol, 2,2”-methylenebis(4-methyl-6
-t-butylphenol), 4.4゛-thiobis(3-
methyl 6-t-butylphenol), 4.4゛-butylidenebis(3-methyl-6-t-butylphenol),
Stearyl-β(3,5-di-4-butyl 4-hydroxyphenyl)propionate, 1.1.3-)lis(2
-methyl-4-hydroxy-5-t-butylphenyl)
Butane, 1.3.5-trimethyl-2,4,6-)lis(3,5-di-t-butyl-4-hydroxybenzyl)
Benzene, octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, tetrakis[methylene-3(3',5'-di-butyl-4'-hydroxyphenyl)propionate comethane etc.

As sulfur-based ones, dilauryl-3,3'-thiodipropionate, cimilistyl-3,3'-thiodipropionate, laurylstearylthiodipropionate,
Examples include distearyl-3'-thiodipropionate and ditridecyl-3,3'-thiodipropionate.

Examples of phosphorus-based substances include trinonylphenyl phosphite and triphenyl phosphite.

Particularly preferred among these are phenolic antioxidants and phosphorus antioxidants.

In particular, 2,6-di-t-butyl-p-cresol (BHT)
) and low-volatility high molecular weight cresol-type antioxidants (product name 1reganox 1010+ Ireganox
1076+Topano ICA, Ionox 33
It is effective to use one or more, especially two or more of them in combination, such as dilauryl thiodipropionate, distearyl thiodipropionate, dialkyl phosphate, etc.

The total amount added is preferably 0.001 to 2.0% by weight, whether used alone or in combination of two or more.

If the amount added is less than 0.001% by weight, there is almost no effect of the addition. On the other hand, if the amount added exceeds 2.0% by weight, it may have an adverse effect on photographic films that utilize oxidation and reduction effects, and abnormalities may occur in performance. For this reason, it is preferable to add the antioxidant in the minimum amount that will not cause color failure or splat.

Commercially available products include various types of Irganox from Ciba Geigy, and 5usilizer BHR and Sumil from Sumitomo Chemical.
iz-er B11-76+ Sumiltzer W
There are X-R, Sumilizer BP-101, etc.

Further, when an antioxidant is further used in combination with carbon black or the like, the antioxidant effect is synergistically exerted.

Preferred lubricants are silicone-based lubricants such as various grades of dimethylpolysiloxane, fatty acid amide-based lubricants such as oleic acid amide, stearic acid amide, erucic acid amide, and bis-fatty acid amide, and alkylamine-based lubricants such as electrostripper. Examples include TS-2 (Kao Soap).

Further, typical examples of additives are described below, but the present invention is not limited thereto, and additives can be selected from all known additives.

(Additive type) (Representative example) (1) Plasticizer;
Phthalate esters, glycol esters, fatty acid esters, (2) Stabilizers; lead-based, cadmium-based, zinc-based, alkaline earth metal-based, organotin-based, etc. (3) Antistatic agents; cationic surfactants, anionic Ionic surfactants, nonionic surfactants, double-sided active agents, various carbon blacks, metal powders, graphite, etc. (4) Flame retardants; phosphoric acid esters, halogenated phosphoric acid esters, halides, no substances, phosphorus-containing polyols etc. (5) Fillers; alumina, kaolin, clay, calcium carbonate, mica, talc, titanium oxide, silica, etc. (6) Reinforcers; glass roving, metal fiber, glass fiber, glass milled fiber, carbon fiber, etc. (7) Colorant: Inorganic pigment (AL FezO, Tt
02゜ZnO, CdS, etc.), organic pigments (carbon black, dyes, etc.), etc. (8) Blowing agents; inorganic blowing agents (ammonia carbonate, soda bicarbonate), organic blowing agents such as thoron-based, azo-based), etc. (9) Prevention of deterioration Agents: UV absorbers, antioxidants, metal deactivators, peroxide decomposers, etc. (10) Coupling agents: Silane-based, titanate-based, chromium-based, aluminum-based, etc. (11) Deodorants, water-absorbing agents , oxygen absorber, fragrance agent, dehumidifier,
Water-absorbing resin, etc.

The packaging material for photosensitive substances of the present invention can be used for packaging various products, including photographic photosensitive materials, foodstuffs, pharmaceuticals,
Suitable for packaging photosensitive materials such as chemicals.

In particular, silver halide photographic materials whose quality is destroyed by small amounts of gas, light, or humidity, photofixable heat-sensitive materials, diazo photographic materials, photosensitive resins, ultraviolet curing materials, and photosensitive materials for lithographic printing; It is suitable for photographic materials such as direct positive photographic materials, self-developing photographic materials, diffusion transfer photographic materials, and photosensitive heat-sensitive materials.

When the packaging material for photosensitive materials of the present invention is applied to, for example, the above-mentioned photosensitive materials, it can be applied to - vertical bags, double flat bags, self-standing bags, - heavy gusset bags, double gusset bags, laminated films, moisture-proof boxes, etc. It can be used for all known forms such as external pasting, inner pasting of light-shielding magazines loaded in bright rooms, and leader paper.
Ru.

The bag making method is based on conventionally known plastic film sealing methods such as heat sealing, fusing sealing, impulse sealing, ultrasonic sealing, and high frequency sealing, depending on the properties of the laminated film used. Note that it is also possible to make bags using an appropriate adhesive, adhesive, or the like.

[Effect]

In the packaging material for photosensitive materials of the present invention, a multilayer coextruded uniaxially oriented film is formed with an HDPE resin film layer and an L-LD film layer.
Because it has a structure of PE resin film layer, L-LDPE
It has excellent heat sealability, tear strength, and impact puncture strength, which are the advantages of resin, and the lack of tensile strength, abrasion resistance, and small Young's modulus is compensated for by heat resistant HDPE resin, which improves heat sealability, physical strength, and heat resistance. All properties shall be excellent.

Since this film has a structure in which it is laminated with at least one other uniaxially molecularly oriented film so that the molecular orientation axes intersect, the physical strength of the film, particularly tear strength, burst strength, and heat seal strength, is improved. It has improved significantly.

〔Example〕

Examples of the packaging material for photosensitive materials of the present invention are shown in FIGS.
This will be explained based on FIG.

1 to 12 are partial cross-sectional views showing the layer structure of the packaging material for photosensitive materials. Arrows in the figure indicate the direction of molecular orientation.

The packaging material for photosensitive materials shown in FIG.
A multilayer coextruded diagonal uniaxial molecularly oriented film Ia consisting of a PE resin film layer 1a and an L-LDPE resin film layer 2a and a diagonal uniaxial light-shielding thermoplastic resin film 8a are laminated with an adhesive layer 3.

The packaging material for photosensitive materials shown in FIG. 2 includes the same multilayer coextruded diagonally uniaxially uniaxially oriented film Ia as shown in FIG.
A is laminated with an adhesive layer 3.

The packaging material for photosensitive materials shown in FIG.
L-L containing PE resin film IJ1a and light-shielding substance
Multilayer coextrusion vertical 1 consisting of DPE resin film layer 2a
An axial molecularly oriented film Ia and an obliquely uniaxially oriented light-shielding thermoplastic resin film 8a are laminated with an adhesive layer 3.

The packaging material for photosensitive materials shown in FIG.
A multilayer coextruded vertically uniaxial molecularly oriented film Ia consisting of a DPE resin film layer 2a and a horizontally oriented thermoplastic resin film 7 processed with a metal thin film processed layer 6 are bonded N.
3 is laminated.

The packaging material for photosensitive materials shown in Fig. 5 consists of a multilayer coextruded vertically uniaxially molecularly oriented film (2) consisting of an HDPE@4 resin film layer 1 and an L-LDPE resin film layer 2, which do not contain light-shielding substances, and a metal thin film. A cross-laminated film having a processed layer 6 is laminated with an adhesive layer 3a containing a light-shielding substance.

The packaging material for photosensitive materials shown in Fig. 6 is composed of the multilayer coextruded @111 molecularly oriented film Ia shown in Fig. 3, the metal thin film processed flexible sheet 7, and the cross-laminated film (-axis distribution oriented film so that the molecular orientation axes intersect). (2 laminated films) are laminated with an adhesive layer 3.

The packaging material for photosensitive materials shown in FIG. 7 is made by laminating a multilayer coextruded longitudinally uniaxial molecularly oriented film Ia, a metal foil 11, and a horizontally oriented thermoplastic resin film 8 with an adhesive layer 3, respectively.

The packaging material for photosensitive materials shown in FIG. 8 includes a multilayer coextruded longitudinally uniaxial molecularly oriented film Ia, a horizontally uniaxially oriented thermoplastic resin film 8, and a longitudinally uniaxially oriented light-shielding thermoplastic resin film 8.
A is laminated with adhesive N3.

In the packaging material for photosensitive materials shown in FIG. 9, a diagonal uniaxially oriented thermoplastic resin film 8 and a horizontally uniaxially oriented thermoplastic resin film 7 processed into metal thin films are adhered to both sides of a multilayer coextruded longitudinally uniaxially oriented film Ia using N3. Each layer is laminated.

The packaging material for a photosensitive material shown in FIG. 10 is a flexible sheet 7 processed with a metal thin film with an adhesive layer 3 on a light-shielding thermoplastic resin film 8a with diagonal uniaxial molecular orientation of the packaging material for a photosensitive material shown in FIG.
It is a layered structure.

FIG. 11 shows a multilayer coextruded uniaxially oriented film Ia having the same layer structure as that in FIG.

Figure 12 shows a multilayer coextruded diagonally uniaxial molecularly oriented film with the same layer structure as that shown in Figure 1 inside the flexible sheet 50 with adhesive layers 3 on both sides! A is laminated with a metal thin film-processed diagonally uniaxial molecularly oriented thermoplastic resin film 7 on the outside.

Next, the results of an experiment comparing the characteristics of the products I to (1) of the present invention and the conventional products I to (2) will be explained.

Invention product■ The product (2) of the present invention corresponds to the layer structure shown in FIG.

The HDPE resin film layer 1a has an MI of 0.4 g/1
HDPE resin 9 resin 9 resin 25, 1111 has a density of 0.964 g/c1a at 0 minutes.

The L-LDPE resin film layer 2a has Ml of 2 and 1
L-LD is a copolymer resin of ethylene and 4-methylpentene-1 with a density of 0 and 920 g/cj at g/10 min.
75.25% by weight of PE resin, 4.5% by weight of oil furnace carbon black, and 0.05% of oleic acid amide.
% by weight, and 0.2% by weight of phenolic antioxidant,
MI is 0, density is 0, 954g/c at 9g/10min
1 of d (consisting of 20% by weight of DPE resin, thickness 25I)
! It is m.

A multilayer coextruded diagonal uniaxial molecularly oriented film made of these layers is diagonal at 45 degrees! Axial molecular orientation. - The axially oriented thermoplastic resin film layer 8a contains 4.5% by weight of carbon black, has an Ml of 0.4g/10min, and has a density of 0.
, thickness 504 using HDPE resin of 964g/aa
This is a light-shielding HDPE resin film uniaxially stretched at an angle of 45 degrees.

Then, they are laminated via an LDPE resin extrusion laminate adhesive layer 3 having a thickness of 1O-, such that the molecular orientation axis is 90 degrees.

Invention product■ The product (2) of the present invention corresponds to the layer structure shown in FIG.

HDPE resin film layer 1aSL-LDP
E The resin composition and thickness of the resin film layer 2a and the adhesive layer 3 are the same as those of the invention product (2). However, a multilayer coextruded longitudinally-axis molecularly oriented film Ia was obtained by an blown silon film molding method.

One or more different uniaxially oriented films include HDPE resin 7 resin 79 and 4 methylpentene-1 copolymer containing 2% titanium oxide with an MI of 0,4 g/10 min and a density of 0,964 g/c A cross with a thickness of lOOgn made by laminating two 45-thick 45-degree diagonally axially stretched HDPE resin films 8 using 20% by weight of the combined resin with a 10-thick adhesive layer so that the molecular orientation axes intersect. A laminate film was used.

The metal thin film processing layer 6 used a 400-layer aluminum vacuum-deposited film, and the flexible sheet 5 used a biaxially stretched nylon resin film with a thickness of 15 mm.

As the adhesive layer 3, an LDPE resin extrusion laminate adhesive layer having a thickness of 15 m was used.

Invention product■ The product (2) of the present invention corresponds to the layer structure shown in FIG.

The HDPE resin film layer 1a, the L-LDPE resin film layer 2a, the diagonally uniaxially stretched light-shielding HDPE resin film 8a, and the adhesive layer 3 are the same as in the product (2) of the present invention. For the metal thin film processing layer 6, an aluminum vacuum-deposited film made by 400 people was used.

Conventional product I The conventional product (3) corresponds to the layer structure shown in FIG.

The HDPE resin film 9a is a light-shielding film with a thickness of 100p manufactured by a blown film molding method using an HDPE resin containing 3% by weight of furnace carbon black, an MI of 0, 4g/10 min, and a density of 0, 964g/d. It is an HDPE resin film.

Conventional product ■ The conventional product (3) corresponds to the layer structure shown in FIG. 15.

The metal foil 11 is an aluminum foil with a thickness of 7 mm.

- The axially stretched film 8a contains 4.5% by weight of carbon black, has an MI of 0.4g/10min, and has a density of 0.964.
This is a light-shielding HDPE resin film made of HDPE resin of g/cffl and uniaxially stretched at a 45 degree angle to a thickness of 45 mm.

Adhesive N3 is an LDPE resin extrusion laminate adhesive layer with a thickness of 13-.

The crossing angle of the stretching axes of the -axis stretched HDPE resin film 8a is 90 degrees.

Conventional product■ The conventional product (2) corresponds to the layer structure shown in FIG. 16.

The metal foil 11 is an aluminum foil with a thickness of 7/ffi.

The L-LDPE resin film 10a has the same resin composition as the L-LDPE resin film layer 2a of the product I of the present invention, containing 3% by weight of carbon black, and has a thickness of 50 mm.
It is an LDPE resin film.

The adhesive layer 3 is an LDPE resin extrusion laminate adhesive layer with a thickness of 15. It is.

Conventional product ■ Conventional product (2) corresponds to the layer structure of the 14th tooth.

LDPE resin film This is a light-shielding LDPE resin film with a thickness of 50 mm and containing 3% by weight of carbon black.

The metal foil 11 is an aluminum foil with a thickness of 7 mm.

The flexible sheet layer 5 is bleached kraft paper with a basis weight of 35 g/rrr.

The adhesive layer 3 is an LDPE resin extrusion laminate adhesive layer with a thickness of 15jM.

The experimental results are shown in Table 1.゛ The evaluation is based on the following.

◎...Excellent O...Excellent...Acceptable (within practical limits) M...Problems (improvement required) ×...Not practical *A Tear strength Complies with JISP8134 *B-side impact puncture strength: Using a Toyo Seiki film impact tester, the drill bit is 2.
The experiment was conducted using a hemisphere and a load of 30 kg-cm.

(However, the measurement was performed on a single laminated film) *C Hot tack property (hot sealability) The open end of two packaging materials (width 15 mm) immediately after heat sealing at 160°C was peeled off with a load of 45 g on each side. angle 2
Measured by hot peel distance (cm) when stretched at 2.5 degrees.

*D Contaminant sealing properties After spreading 150 cigarette butts on the surface of each packaging material, heat sealing is performed, and the sheet strength is measured to determine the strength. *E Heat sealing strength over time. Two samples of film width 15 mm Repeat heat sealing at the desired sealing temperature, sealing pressure 1) Cg/cti, and sealing time 1 second, and after leaving it for 3 months (
(room temperature: 20° C., humidity: 65% RH) Find the load required to peel off the seal surface at a 180 degree angle.

*F Film formability: Simultaneous two-layer coextrusion of each sample using a blown film molding machine. Low current load, bubble stability, and film wrinkles when molding the film at the listed resin formulation and film thickness. *G Bag-making permissibility Comprehensively judges suitability for heat sealing, occurrence of curling and wrinkles, etc. when making flat bags using an automatic bag-making machine using each packaging material.

*H Bursting strength Complies with JISP8112 [Effects of the invention] As described above, the present invention provides tear strength, impact puncture strength,
It has high physical strength such as bursting strength, excellent heat sealability such as hot tack property and impurity sealing property, high heat seal strength over time, good film formability, excellent bag making suitability, and is inexpensive for use with photosensitive materials. Packaging materials can be provided.

[Brief explanation of the drawing]

1 to 12 are partial cross-sectional views showing the layer structure of an example of the packaging material for photosensitive materials of the present invention. 13 to 16 are partial cross-sectional views showing the layer structure of conventional packaging materials. 1, Ia...Multilayer coextruded oblique uniaxial molecular orientation film 1.1a...HDPE resin film layer 5-: 5.5a...Flexible sheet 6...Metal thin film processed layer 7.7a... Metal thin film processing flexible sheet 11・
...Metal foil a: Patent applicant indicating that it contains a light-blocking substance Agent of Fuji Photo Film Co., Ltd.
Japan-China political situation Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 12 Figure 13 Figure 15 Figure 16 Figure 11 Figure 14

Claims (1)

[Claims] A high-density polyethylene resin film layer containing 50% by weight or more of a high-density polyethylene resin having a density of 0.941 g/cm^3 or more, a melt index of 0.1 to 1.0 g/10 minutes, and a softening point of 120°C or more. , density is 0.940g
/cm^3 or less and the melt index is 0.5 to 15.
A multilayer coextruded uniaxially molecularly oriented film having a linear low density polyethylene resin film layer containing 30% by weight or more of a linear low density polyethylene resin of 0 g/10 min and at least one different uniaxially molecularly oriented film, A packaging material for photosensitive materials, characterized in that two or more layers are laminated so that their molecular orientation axes intersect, and at least one layer has a light-shielding property.